Abstract
The aim of the work was to study the morphology and structural features of biodegradable composites based on polylactide, filled with corn starch formed by extrusion method. The characteristics of the obtained materials were investigated by scanning electron microscopy, X-ray diffraction, IR spectroscopy. It was established that the presence of polyethylene glycol PEG–4000 as a plasticizer and surfactant – glycerin monostearate in the initial mixture leads to the formation of a nonporous heterogeneous system, in which starch particles are statistically distributed in the matrix. The starch concentration in the composite varied from 20 to 55 wt. %. When the starch concentration increases to the limit values, agglomeration of filler particles occurs and a sharp deterioration in the mechanical properties of the composite. The XRD analysis of the samples showed that the initial PLA does not actually have a crystalline phase, and when PEG and starch are introduced into the composite, intense reflexes are observed on the diffractogram, which are most likely a superposition of two reflections - from the starch and the crystalline phase of the polylactide. The effect of PEG and starch on the composite structure was analyzed using the IR spectroscopy method. No new bands were found in the spectrum of the composite compared to the IR spectrum of the original polylactide, which indicates the absence of chemical interaction between the components. The most intense bands in both samples are located in the region of 1200-1750 cm–1 and relate to the valence vibrations of C–O bonds (C–O–C and / or C–O(H)), as well as to the valence vibrations of C–C bonds, i.e. only polylactide is present on the surface of the sample, and the surface. The composite is a plasticized polylactide, interspersed with starch particles coated with a polymer film. In addition, in the IR spectrum of the composite, the band corresponding to the valence vibrations of bound hydroxyl groups (3200–3500 cm–1) has a significantly higher intensity and width, which indicates an additional contribution of OH- groups present in the PEG molecule. Biodegradability tests conducted in accordance with the international standard ISO 16929:2013 showed that the obtained materials undergo complete chemical and biological destruction in compost within 5–6 months.
Recommended Citation
PODDENEZHNY, Eygeniy N.; BOIKO, Andrei A.; TRUSOVA, Ekaterina E.; and SHAPOVALOV, Viktor M.
(2025)
"STRUCTURAL FEATURES AND MORPHOLOGY OF BIODEGRADABLE COMPOSITES BASED ON POLYLACTIDE AND CORN STARCH,"
CHEMISTRY AND CHEMICAL ENGINEERING: Vol. 2024:
No.
4, Article 4.
DOI: https://doi.org/10.59048/cce202444
Available at:
https://cce.researchcommons.org/journal/vol2024/iss4/4